For a vacation, you and your family fly east to west from Boston, Massachusetts, to Seattle, Washington. You notice that your flight back home to Boston is shorter than your flight to Seattle.Which phenomenon causes your flight home to be shorter?

The jet stream is a band of fast-moving air that generally flows from west to east. A flight from Seattle back to Boston travels eastward and can get a tailwind from the jet stream, helping it arrive sooner; the westbound flight may face that airflow instead. So the correct choice is the jet stream.

AI-written and checked against the verified answer.